• Journal of the Optical Society of Korea
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• v.10 no.3
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• pp.124-129
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• 2006

We have developed a compact and cost-effective camera module on the basis of wafer-scale-replica processing. A multiple-layered structure of several aspheric lenses in a mobile-phone camera module is first assembled by bonding multiple glass-wafers on which 2-dimensional replica arrays of identical aspheric lenses are UV-embossed, followed by dicing the stacked wafers and packaging them with image sensor chips. This wafer-scale processing leads to at least 95% yield in mass-production, and potentially to a very slim phone with camera-module less than 2 mm in thickness. We have demonstrated a VGA camera module fabricated by the wafer-scale-replica processing with various UV-curable polymers having refractive indices between 1.4 and 1.6, and with three different glass-wafers of which both surfaces are embossed as aspheric lenses having $230{\mu}m$ sag-height and aspheric-coefficients of lens polynomials up to tenth-order. We have found that precise compensation in material shrinkage of the polymer materials is one of the most technical challenges, in orderto achieve a higher resolution in wafer-scaled lenses for mobile-phone camera modules.

• Journal of Fashion Business
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• v.22 no.2
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• pp.27-39
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• 2018

This study analyzed the body shape of women over 70 years and classified their body shapes in order to provide basic data for the development of pants patterns that can complement the weakness of the body shape of elderly women. It were analyzed using SPSS Ver. 20.0. Five factors were extracted from the lower body: obesity and thigh thickness, lower body length, under knee thickness, ankle height, and hip sag. In type 1, the lower body was obese and the legs were thick, but the hips were not sagging. It was named 'high-hip obesity figure'. Type 2's abdomen, hip, and waist were obese, but the legs were thin and the hip were not sagging. Thus, 'bird-leg middle obesity figure' was the name. Type 3 had a long and slender lower body, but legs were thick and the hips were saggy, it was named 'strong-leg low-hip slender figure'. The elderly women showed less difference in waist, abdomen, and hip circumference. The abdominal circumference was 2-3cm more than the waist and hip circumference; hence there is a need to differentiate the shape and number of darts in the production of bottom-wear patterns for older women. In addition, the leg circumference is gradually reduced by aging compared to the size of the lower body. Therefore, it would be necessary to search for a method that can effectively design the difference between the hip circumference and the leg circumference in relation to the body shape and the aesthetics of older women.

• Korean Journal of Optics and Photonics
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• v.16 no.6
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• pp.508-515
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• 2005

We propose a fabrication method for refractive lens by variable velocity moving mask lithography and slit pattern. Distribution of exposure dose should be controlled for the curved photoresist surface that works as a refractive surface. We analyze theoretically the distribution of exposure dose by change of moving velocity, moving direction of mask and the shape of mask pattern, and confirm for the curved surface experimentally. The lens could have sag height of a few of hundreds ${\mu}m$, by using thick photoresist or Deep RIE process.

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.21-32
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• 2017

The objective of this study is to analysis the mechanical characteristics on the geometric nonlinear behavior of radial cable roof systems for long span retractable cable roof structures. The retractable roof is designed as a full control system to overcome extreme outdoor environments such as extreme hot or cold weather, strong wind or sunlight, and the cable roof greatly can reduce roof weight compared to other rigid structural system. A retractable cable roof system is a type of structures in which the part of entire roof can be opened and closed. The radial cable roof is an effective structural system for large span retractable roofs, the outer perimeter of the roof is a fixed membrane roof and the middle part is a roof that can be opened and closed. The double arrangement cables of a radial cable truss roof system with reverse curvature works more effectively as a load bearing cables, the cable system can carry vertical load in up and downward direction. In this paper, to analyze the mechanical characteristics of a radial cable roof system with central posts, the authors will investigate the tensile forces of bearing cables, stabilized cables, ring cables, and the deflection of roof according to the height of the post or hub that affects the sag ratio of cable truss. The tensile forces of the cables and the deflection of the roof are compared for the cases when the retractable roof is closed and opened.